But with atomic clocks tracking the Earth’s rotational speed so closely that once every year and a half or so, the International Earth Rotation and Reference Systems Service (yes, there is such a thing) has to add a leap second to the year to account for any increase in the planet’s speed,

On July 9, 2025, scientists at the International Earth Rotation and Reference Systems Service (IERS) reported that the Earth completed its rotation approximately 1.3 to 1.6 milliseconds faster than the standard 24-hour period. Moreover, this is expected to happen again on July 22 and August 5 this year.

July 9 was predicted to have a shorter "length of day" than usual due to an increase in Earth's rotation speed. See which other days will be shorter